In advanced technologies of integrated circuit industry, strained semiconductor structures are used to increase the carrier mobility in the channel and enhance circuit performance. Epitaxy growth is a step implemented to form the strained structure. However, the epitaxy growth is sensitive to the structure of the active regions and the corresponding environment. In one example, facet defects are formed and constrain further epitaxy growth. Therefore, a structure of an integrated circuit and a method making the same are needed to address the issues identified above.